This invention relates to watercraft and aircraft and more particularly to a watercraft and aircraft in which a main wing supports the cabin in the case of a watercraft and supports the fuselage in the case of an aircraft when the aircraft is in water.
Various flotation means are used to support a seaplane when it is on water. The most usual means are floats or pontoons but in some aircraft such as flying-boats, a portion of their fuselage as well as outboard floats are used to support them on water.
The pontoons and floats of conventional float-planes detrimentally affect the operation of the craft in a number of ways: first the pontoons and floats constitute a substantial aerodynamic drag when the aircraft is taking off and when the aircraft is in the air and secondly the air speed of the aircraft and its fuel efficiency are detrimentally affected by such drag.
Flying-boats, which are supported by their fuselage as well as by pontoons and floats, also have substantial drag due to the floats attached to their wings. There is however another source of drag which is due to so called “shed-vortex” drag associated with the hydrodynamic “step” located on the bottom of their fuselages.
The step allows the aircraft to break water suction forces and to become “unstuck” and to lift off the water once sufficient speed has been attained. As much as 50 percent of the overall drag of a standard flying-boat or a float-plane is attributable to the shed-vortex drag of this step.